The invention relates to motion detection and control systems for automated, power-driven pool and tank cleaning apparatus.
Automated, power-driven pool and tank cleaners have been provided with programmable circuit control devices to provide random and/or regular patterns of movement of the apparatus. The purpose of these devices is to maximize the probability that the apparatus will cover the entire bottom wall surface during the cleaning operation. Some pool cleaners are designed and programmed accordingly for cleaning the generally vertical side walls, as well as the bottom wall of the pool or tank.
Control devices are known that produce a change in direction after a predetermined period of time. Other control devices respond to signals generated by mercury switches that change with the orientation from horizontal to vertical, or when a projecting rod, proximity device, or the like senses that the apparatus is adjacent a wall.
These prior art methods and apparatus for controlling the direction of movement do not take into account the possibility that the apparatus may be stopped by an obstacle, or that much of the directional cycle may be spent with the apparatus stalled in a corner or other pool contour.
It is therefore an object of this invention to provide a method and apparatus for determining whether the apparatus is actually moving across a wall surface that is to be cleaned or whether the relative movement of the apparatus has stopped and, in the event that relative movement has ceased, to thereafter cause the apparatus drive means to move the apparatus in a different direction.
It is a further object of the invention to provide a method and apparatus for detecting the relative motion of the apparatus that are responsive to changes in the contour of the surface being cleaned.
The above objects and other advantages are obtained by the method and apparatus of the invention which comprehends providing an automated power-driven pool cleaning apparatus which includes a programmable control device for directing the movement of the apparatus with elements comprising:
a motion translating member (xe2x80x9cmtmxe2x80x9d) mounted for contacting the surface of the wall being cleaned, said motion translating member moving as said apparatus moves across the wall;
a signal transmitter for transmitting signals in accordance with movement of said motion translating member; and
a sensor mounted to receive signals from said signal transmitter and for providing an output indicative of signals received to the control device,
wherein the programmable control device is programmed to alter the direction of movement of said apparatus when the output of said sensor indicates that said apparatus has not moved within a prescribed period of time.
In accordance with the method of the invention for controlling movement of an automated power-driven pool cleaning apparatus, the apparatus comprising a programmable control device for directing movement of the apparatus, the method comprising the steps of:
providing a motion translating member mounted on the apparatus for contacting the surface of the wall being cleaned, the motion translating member including at least one signal transmitter that moves as the apparatus moves across the wall;
providing a sensor mounted on the apparatus to receive signals from the signal transmitter;
transmitting signals from the signal transmitter in relative to the accordance with movement of the motion translating member;
outputting from the sensor to the programmable control device, an output signal that is indicative of signals received from the signal transmitter by the sensor; and
changing a direction of movement of the apparatus under control of the programmable control device when the output indicates that the apparatus has not moved within a prescribed period of time.
The motion translating member can take the form of a wheel, a continuous belt or other element that extends from the body of the pool cleaner apparatus to contact the wall that is being cleaned. The mtm is mounted so that it moves freely as the apparatus traverses the bottom and/or side walls of the pool. The mtm stops moving when the apparatus stops moving, e.g., when the apparatus encounters an obstacle, a vertical sidewall (if the cleaner is designed only to clean the bottom wall), or the surface of the water when on a side wall. As will be explained in more detail below, when the mtm stops for a pre-determined period of time, an associated signal transmitter ceases to transmit an intermittent signal to a nearby sensor, and the program of the electronic control device causes the drive means to stop and then to reverse the direction of the cleaner.
The mtm is preferably mounted to extend downwardly beneath the body of the cleaner, between the drive means and in a position where it is protected from side impact.
The mtm can be in the form of a wheel that is mounted on an axle, which in turn is mounted for vertical displacement in response to a biasing force that urges the mtm into contact with the wall below the apparatus. Thus, the portion of the mtm in contact with the wall moves in response to depressions, e.g., recessed drains, or to raised areas and other irregularities typically found on the walls of a pool and which do not impede the progress of the apparatus in the pursuit of its cleaning program.
The mtm can take the form of an endless belt or track, one or more of the supporting pulleys or sprockets of which is mounted as described above to assure that the portion of the belt extending below the apparatus maintains contact with the surface being cleaned. The mechanism for this embodiment can include one or more idler rollers to provide the necessary tension and expansion for the belt.
The mtm is provided with at least one signal transmitter that is mounted for movement with the mtm. The signal transmitter can take the form of one or more permanent magnets, each of which emanates a separate magnetic force field; a point source of light; one or more apertures that permit the passage of light from a fixed light source adjacent the mtm; or other equivalent devices which will be apparent to those of ordinary skill in the signal generation, control and detection art.
A sensor is positioned proximate the mtm to receive and respond to the signal from the transmitter. The sensor is also in communication with the programmed control device. In a preferred embodiment, the sensor is hard-wired to the device. However, infrared and short range radio transmission technology can be utilized to link the sensor and the control device.
When the apparatus is moving, one or more signal transmitters mounted in the mtm will provide an intermittent signal to the sensor as it moves past the sensor. In turn, the sensor communicates this data to the control device. When the apparatus stops, as by having its movement interrupted by an obstacle, no intermittent signal is received by the sensor. After a prescribed period of time, the control device program causes the drive means to reverse or otherwise change the direction of movement of the apparatus.
The control device is programmed to process a continuous signal from the transmitter to the sensor in the same manner as no signal. Thus, if the mtm stops so that a magnet, or light source, or light-transmitting aperture is providing a continuous signal to the sensor for more than the predetermined interval, the apparatus will be reversed.
The use of the apparatus and method of the invention provides an inexpensive and reliable solution to the problem of maintaining a continuous pattern of movement for the apparatus. Placement of the mtm inboard and beneath the body of the cleaner minimizes its exposure to damaging impacts, both in and out of the pool. The number of moving parts is minimal, their assembly and mode of operation is straight-forward, and they can be made from known materials to assure long-term use without failure.